]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blame_incremental - fs/reiserfs/xattr_acl.c
UBUNTU: Ubuntu-4.10.0-37.41
[mirror_ubuntu-zesty-kernel.git] / fs / reiserfs / xattr_acl.c
... / ...
CommitLineData
1#include <linux/capability.h>
2#include <linux/fs.h>
3#include <linux/posix_acl.h>
4#include "reiserfs.h"
5#include <linux/errno.h>
6#include <linux/pagemap.h>
7#include <linux/xattr.h>
8#include <linux/slab.h>
9#include <linux/posix_acl_xattr.h>
10#include "xattr.h"
11#include "acl.h"
12#include <linux/uaccess.h>
13
14static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th,
15 struct inode *inode, int type,
16 struct posix_acl *acl);
17
18
19int
20reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
21{
22 int error, error2;
23 struct reiserfs_transaction_handle th;
24 size_t jcreate_blocks;
25 int size = acl ? posix_acl_xattr_size(acl->a_count) : 0;
26
27
28 /*
29 * Pessimism: We can't assume that anything from the xattr root up
30 * has been created.
31 */
32
33 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
34 reiserfs_xattr_nblocks(inode, size) * 2;
35
36 reiserfs_write_lock(inode->i_sb);
37 error = journal_begin(&th, inode->i_sb, jcreate_blocks);
38 reiserfs_write_unlock(inode->i_sb);
39 if (error == 0) {
40 error = __reiserfs_set_acl(&th, inode, type, acl);
41 reiserfs_write_lock(inode->i_sb);
42 error2 = journal_end(&th);
43 reiserfs_write_unlock(inode->i_sb);
44 if (error2)
45 error = error2;
46 }
47
48 return error;
49}
50
51/*
52 * Convert from filesystem to in-memory representation.
53 */
54static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size)
55{
56 const char *end = (char *)value + size;
57 int n, count;
58 struct posix_acl *acl;
59
60 if (!value)
61 return NULL;
62 if (size < sizeof(reiserfs_acl_header))
63 return ERR_PTR(-EINVAL);
64 if (((reiserfs_acl_header *) value)->a_version !=
65 cpu_to_le32(REISERFS_ACL_VERSION))
66 return ERR_PTR(-EINVAL);
67 value = (char *)value + sizeof(reiserfs_acl_header);
68 count = reiserfs_acl_count(size);
69 if (count < 0)
70 return ERR_PTR(-EINVAL);
71 if (count == 0)
72 return NULL;
73 acl = posix_acl_alloc(count, GFP_NOFS);
74 if (!acl)
75 return ERR_PTR(-ENOMEM);
76 for (n = 0; n < count; n++) {
77 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
78 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
79 goto fail;
80 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
81 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
82 switch (acl->a_entries[n].e_tag) {
83 case ACL_USER_OBJ:
84 case ACL_GROUP_OBJ:
85 case ACL_MASK:
86 case ACL_OTHER:
87 value = (char *)value +
88 sizeof(reiserfs_acl_entry_short);
89 break;
90
91 case ACL_USER:
92 value = (char *)value + sizeof(reiserfs_acl_entry);
93 if ((char *)value > end)
94 goto fail;
95 acl->a_entries[n].e_uid =
96 make_kuid(&init_user_ns,
97 le32_to_cpu(entry->e_id));
98 break;
99 case ACL_GROUP:
100 value = (char *)value + sizeof(reiserfs_acl_entry);
101 if ((char *)value > end)
102 goto fail;
103 acl->a_entries[n].e_gid =
104 make_kgid(&init_user_ns,
105 le32_to_cpu(entry->e_id));
106 break;
107
108 default:
109 goto fail;
110 }
111 }
112 if (value != end)
113 goto fail;
114 return acl;
115
116fail:
117 posix_acl_release(acl);
118 return ERR_PTR(-EINVAL);
119}
120
121/*
122 * Convert from in-memory to filesystem representation.
123 */
124static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
125{
126 reiserfs_acl_header *ext_acl;
127 char *e;
128 int n;
129
130 *size = reiserfs_acl_size(acl->a_count);
131 ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
132 acl->a_count *
133 sizeof(reiserfs_acl_entry),
134 GFP_NOFS);
135 if (!ext_acl)
136 return ERR_PTR(-ENOMEM);
137 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
138 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
139 for (n = 0; n < acl->a_count; n++) {
140 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
141 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
142 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
143 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
144 switch (acl->a_entries[n].e_tag) {
145 case ACL_USER:
146 entry->e_id = cpu_to_le32(
147 from_kuid(&init_user_ns, acl_e->e_uid));
148 e += sizeof(reiserfs_acl_entry);
149 break;
150 case ACL_GROUP:
151 entry->e_id = cpu_to_le32(
152 from_kgid(&init_user_ns, acl_e->e_gid));
153 e += sizeof(reiserfs_acl_entry);
154 break;
155
156 case ACL_USER_OBJ:
157 case ACL_GROUP_OBJ:
158 case ACL_MASK:
159 case ACL_OTHER:
160 e += sizeof(reiserfs_acl_entry_short);
161 break;
162
163 default:
164 goto fail;
165 }
166 }
167 return (char *)ext_acl;
168
169fail:
170 kfree(ext_acl);
171 return ERR_PTR(-EINVAL);
172}
173
174/*
175 * Inode operation get_posix_acl().
176 *
177 * inode->i_mutex: down
178 * BKL held [before 2.5.x]
179 */
180struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
181{
182 char *name, *value;
183 struct posix_acl *acl;
184 int size;
185 int retval;
186
187 switch (type) {
188 case ACL_TYPE_ACCESS:
189 name = XATTR_NAME_POSIX_ACL_ACCESS;
190 break;
191 case ACL_TYPE_DEFAULT:
192 name = XATTR_NAME_POSIX_ACL_DEFAULT;
193 break;
194 default:
195 BUG();
196 }
197
198 size = reiserfs_xattr_get(inode, name, NULL, 0);
199 if (size < 0) {
200 if (size == -ENODATA || size == -ENOSYS)
201 return NULL;
202 return ERR_PTR(size);
203 }
204
205 value = kmalloc(size, GFP_NOFS);
206 if (!value)
207 return ERR_PTR(-ENOMEM);
208
209 retval = reiserfs_xattr_get(inode, name, value, size);
210 if (retval == -ENODATA || retval == -ENOSYS) {
211 /*
212 * This shouldn't actually happen as it should have
213 * been caught above.. but just in case
214 */
215 acl = NULL;
216 } else if (retval < 0) {
217 acl = ERR_PTR(retval);
218 } else {
219 acl = reiserfs_posix_acl_from_disk(value, retval);
220 }
221
222 kfree(value);
223 return acl;
224}
225
226/*
227 * Inode operation set_posix_acl().
228 *
229 * inode->i_mutex: down
230 * BKL held [before 2.5.x]
231 */
232static int
233__reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
234 int type, struct posix_acl *acl)
235{
236 char *name;
237 void *value = NULL;
238 size_t size = 0;
239 int error;
240
241 switch (type) {
242 case ACL_TYPE_ACCESS:
243 name = XATTR_NAME_POSIX_ACL_ACCESS;
244 if (acl) {
245 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
246 if (error)
247 return error;
248 }
249 break;
250 case ACL_TYPE_DEFAULT:
251 name = XATTR_NAME_POSIX_ACL_DEFAULT;
252 if (!S_ISDIR(inode->i_mode))
253 return acl ? -EACCES : 0;
254 break;
255 default:
256 return -EINVAL;
257 }
258
259 if (acl) {
260 value = reiserfs_posix_acl_to_disk(acl, &size);
261 if (IS_ERR(value))
262 return (int)PTR_ERR(value);
263 }
264
265 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
266
267 /*
268 * Ensure that the inode gets dirtied if we're only using
269 * the mode bits and an old ACL didn't exist. We don't need
270 * to check if the inode is hashed here since we won't get
271 * called by reiserfs_inherit_default_acl().
272 */
273 if (error == -ENODATA) {
274 error = 0;
275 if (type == ACL_TYPE_ACCESS) {
276 inode->i_ctime = current_time(inode);
277 mark_inode_dirty(inode);
278 }
279 }
280
281 kfree(value);
282
283 if (!error)
284 set_cached_acl(inode, type, acl);
285
286 return error;
287}
288
289/*
290 * dir->i_mutex: locked,
291 * inode is new and not released into the wild yet
292 */
293int
294reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
295 struct inode *dir, struct dentry *dentry,
296 struct inode *inode)
297{
298 struct posix_acl *default_acl, *acl;
299 int err = 0;
300
301 /* ACLs only get applied to files and directories */
302 if (S_ISLNK(inode->i_mode))
303 return 0;
304
305 /*
306 * ACLs can only be used on "new" objects, so if it's an old object
307 * there is nothing to inherit from
308 */
309 if (get_inode_sd_version(dir) == STAT_DATA_V1)
310 goto apply_umask;
311
312 /*
313 * Don't apply ACLs to objects in the .reiserfs_priv tree.. This
314 * would be useless since permissions are ignored, and a pain because
315 * it introduces locking cycles
316 */
317 if (IS_PRIVATE(dir)) {
318 inode->i_flags |= S_PRIVATE;
319 goto apply_umask;
320 }
321
322 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
323 if (err)
324 return err;
325
326 if (default_acl) {
327 err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
328 default_acl);
329 posix_acl_release(default_acl);
330 }
331 if (acl) {
332 if (!err)
333 err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS,
334 acl);
335 posix_acl_release(acl);
336 }
337
338 return err;
339
340apply_umask:
341 /* no ACL, apply umask */
342 inode->i_mode &= ~current_umask();
343 return err;
344}
345
346/* This is used to cache the default acl before a new object is created.
347 * The biggest reason for this is to get an idea of how many blocks will
348 * actually be required for the create operation if we must inherit an ACL.
349 * An ACL write can add up to 3 object creations and an additional file write
350 * so we'd prefer not to reserve that many blocks in the journal if we can.
351 * It also has the advantage of not loading the ACL with a transaction open,
352 * this may seem silly, but if the owner of the directory is doing the
353 * creation, the ACL may not be loaded since the permissions wouldn't require
354 * it.
355 * We return the number of blocks required for the transaction.
356 */
357int reiserfs_cache_default_acl(struct inode *inode)
358{
359 struct posix_acl *acl;
360 int nblocks = 0;
361
362 if (IS_PRIVATE(inode))
363 return 0;
364
365 acl = get_acl(inode, ACL_TYPE_DEFAULT);
366
367 if (acl && !IS_ERR(acl)) {
368 int size = reiserfs_acl_size(acl->a_count);
369
370 /* Other xattrs can be created during inode creation. We don't
371 * want to claim too many blocks, so we check to see if we
372 * we need to create the tree to the xattrs, and then we
373 * just want two files. */
374 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
375 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
376
377 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
378
379 /* We need to account for writes + bitmaps for two files */
380 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
381 posix_acl_release(acl);
382 }
383
384 return nblocks;
385}
386
387/*
388 * Called under i_mutex
389 */
390int reiserfs_acl_chmod(struct inode *inode)
391{
392 if (IS_PRIVATE(inode))
393 return 0;
394 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
395 !reiserfs_posixacl(inode->i_sb))
396 return 0;
397
398 return posix_acl_chmod(inode, inode->i_mode);
399}